JPH10134937A - Heater, heating device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide even fixing property by forming the surface of a heater at a side for heating a material to be heated with a pattern of the material having a thermal conductivity lower than that of the base material of the heater, and setting a desirable distribution of heat supplied variable in the heating surface. SOLUTION: A surface of a heater 1, which is formed with a pattern layer 13 having a low thermal conductivity, is exposed downward, and the heater 1 is fitted in a groove 20a, which is provided in a lower surface of a heater holder 20 along the longitudinal direction of the holder, and fixed for support. The pattern layer 13 having a low thermal conductivity, which is formed in a surface side of the heater, corrects the temperature distribution in the longitudinal direction of a fixed nip part N so as to even the distribution of the hat supplied variable in the longitudinal direction of the fixed nip part N. A pattern of a glass coat 13 is provided as a pattern layer 13 having a low thermal conductivity, and a desirable distribution of heat supplied variable is obtained in a heating surface for heating a material to be heated, and even fixing property can be thereby obtained in a heating and fixing device of an image forming device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating member for heating a material to be heated, a heating device provided with the heating member, and an image forming apparatus provided with the heating device as a heat fixing device.

[0002]

2. Description of the Related Art For example, a heat fixing device in an image forming apparatus such as an electrophotographic copying machine, a printer, a facsimile, etc., that is, an image forming process means such as electrophotography, electrostatic recording, magnetic recording, etc. Indirect (transfer) to the surface of the recording material (transfer material sheet, printing paper, electrofax sheet, electrostatic recording sheet, etc.) using an agent (toner)
Conventionally, as a heating device for thermally fixing an unfixed developer image corresponding to target image information formed and supported by a system or a direct system on a surface of a recording material, a heat roller system has been widely used. Was.

[0003] The heating device of the heating roller type uses a pressure nip between a heating roller (fixing roller) heated by a built-in heat source such as a halogen heater to maintain a predetermined temperature, and an elastic pressure roller pressed against the heating roller. The recording material is introduced into a fixing portion (fixing nip portion), and is nipped and conveyed, whereby the unfixed developer image on the recording material surface is thermally fixed by the heat of the heating roller.

However, in this heat roller type apparatus, the temperature of the heating roller must be constantly maintained at a high level so that an image can be output immediately at any time, which consumes a large amount of energy. Even during the standby time, heat was released into the cabin, causing a problem of increasing the cabin temperature. Also, a considerable waiting time is required after the power is turned on until the heating roller rises to a predetermined temperature suitable for heating the recording material as the material to be heated.

Recently, a heating apparatus of a film heating type has been proposed and put into practical use (Japanese Patent Laid-Open No. 63-31818).
No. 2, Japanese Patent Laid-Open No. 1-263679, Japanese Patent Laid-Open No. 2-263679
No. 157878 / JP-A-4-44075-4408
No. 3, JP-A-4-20498-204498).

In this heating apparatus, a material to be heated is brought into close contact with a heating body fixedly supported by a supporting member via a heat-resistant and thin film material, and the film material is slid and moved to the heating body to heat the heating body. Is applied to a material to be heated via a film material, and can be used as an apparatus for thermally fixing an unfixed toner image as a permanently fixed image on the surface of a recording material carrying the image. Further, for example, it can be widely used as a device for heating a recording material carrying an image to improve the surface properties such as gloss and the like, a device for performing a hypothetical deposition process, and a device for heating a sheet-shaped material to be heated.

In such a film heating type heating apparatus, a heating element having a high heat-up rate and a low heat capacity, for example, a ceramic substrate having an insulating property and a good thermal conductivity, and a surface provided on the substrate are provided. It is possible to use a so-called ceramic heater having a resistance heating layer that generates heat by energization as a basic component, and a thin film having a low heat capacity can be used as a film material. ,
There is no need to supply power to the heating element during standby, and even if the recording medium as the heating element is immediately passed, the heating element is sufficiently heated to a predetermined temperature until the recording element reaches the fixing portion. It has the advantages of shortening the wait time (quick start: operating on demand), saving power, and reducing the temperature rise inside the machine such as an image forming apparatus. Have and be effective.

FIG. 14 is a schematic cross-sectional view of a main part of an example of a film heating type heating device (heating fixing device), and FIG.
Is a partially cutaway front side model view of the heating body of the apparatus, (b) is a back side model view of the heating body, and (c) is an enlarged cross-sectional model view ((b)) of a heating element portion of the heating body. (C) is an enlarged cross-sectional model diagram along line (c)-(c).

Reference numeral 10 denotes a heating element (hereinafter referred to as a heater),
Reference numeral 20 denotes a heater supporting member (heater holder (stay), hereinafter referred to as a heater holder) which fixedly supports the heater 10 on the lower surface, and 21 denotes a heat-resistant and thin film material (hereinafter, referred to as a heater holder).
Reference numeral 22 denotes an elastic pressure roller.

The heater 10 fixedly supported on the lower surface of the heater holder 20 and the elastic pressure roller 22 are pressed against each other with a predetermined pressing force against the elasticity of the elastic pressure roller 22 with the fixing film 21 interposed therebetween. A heating nip portion (hereinafter, referred to as a fixing nip portion) N having a width is formed.

Generally, a ceramic heater is used as the heater 10, and the heater is heated and controlled to a predetermined temperature by energization. The structure of the heater 10 will be described later.

The fixing film 21 has a thickness of, for example, 40 μm.
It is a heat-resistant film material having a thin single-layer or composite-layer structure such as polyimide having a thickness of about 100 μm, and is a cylindrical or endless belt-shaped or roll-wrapped end web-shaped member. The fixing film 21 is conveyed and moved in a direction indicated by an arrow while the inner surface of the film is in close contact with the lower surface of the heater 10 at the fixing nip portion N by the driving means (not shown) or the rotational force of the elastic pressure roller 22.

The heater holder 20 is, for example, a heat-resistant plastic member, which holds the heater 10 and also serves as a conveyance guide for the fixing film 21.

In a state where the fixing film 21 is transported and moved, and the heater 10 is heated and controlled to a predetermined temperature, a material to be heated is provided between the fixing film 21 and the elastic pressure roller 22 in the fixing nip N. Unfixed toner image T
When the recording material P on which the image is formed and supported is introduced with the image-bearing surface side facing the fixing film, the recording material P
The fixing nip N is conveyed together with the fixing film 21 in close contact with the outer surface of the fixing film 21.

In the fixing nip portion N, the recording material P
The toner image T is fixed on the fixing film 21 by the heater 10.
And the toner image T is heated and fixed on the surface of the recording material P. The recording material portion that has passed through the fixing nip portion N is conveyed separately from the outer surface of the fixing film 21. Ta indicates a toner image fixed by heating.

The heater 10 as a heating element in the present embodiment
Is a ceramic heater, a heater substrate (heating element substrate) 2 and a heating layer (a resistance heating element layer that generates heat by energization) formed on one side (front side) of the heater substrate 2 3, conductive pattern 4, conductive pattern 4
a, two power supply electrode patterns 5.6, heat generating layer pattern 3
And a glass layer 7 as a heater surface protective layer covering the conductor pattern 4 and the other side (back side) of the heater base 2, a thermistor chip 8 as a temperature detecting element, and the thermistor chip 8 About the wiring section (D
C energizing section) 9.9, electrode section (DC electrode section) 9a, 9a, and the like.

The heater base material 2 is a horizontally long and thin wall having a length in a direction perpendicular to the conveying movement direction A of the fixing film 21 and the recording material P in the fixing nip portion N, for example, a length of 240 mm and a width of 10 mm.・ Heat resistance of 1mm thick ・
An electrically insulating and low heat capacity ceramic material, specifically an alumina plate.

The heating layer pattern 3 on the front side of the heater substrate 2 is made of, for example, silver palladium (Ag / Pb).
・ Electrical resistance material paste such as Ta ₂ N (resistance paste)
Is formed, for example, by coating and firing along a longitudinal direction of the heater substrate surface in a narrow band shape having a thickness of 10 μm and a width of 1 to 3 mm.

The conductor pattern 4 corresponds to the heat generating layer pattern 3 described above.
Are formed along the length of the heater base material in the form of a narrow band substantially parallel to.

The two power supply electrode patterns 5 and 6 are provided side by side on one end surface of the heater substrate 2.

One end of the heating layer pattern 3 is electrically connected to one of the two power supply electrode patterns 5 and 6 via the conductive pattern 4a. One end of the conductor pattern 4 on the same side is electrically connected to the other power supply electrode pattern 6. The other ends of the heat generating layer pattern 3 and the conductor pattern 4 are electrically connected to each other.

The above-mentioned conductive pattern 4, conductive pattern 4
a, the two power supply electrode patterns 5 and 6 are each formed by applying a pattern of a conductive material paste such as Ag on the surface of the heater base material 2 by screen printing or the like and firing it.

The heat generating layer pattern 3 and the conductor pattern 4 which are substantially parallel to each other form a forward path and a return path for energization between the two power supply electrode patterns 5 and 6 provided at one longitudinal end of the heater base 2 with respect to the heater length. doing.

The wiring portions 9 and 9 and the electrode portions 9 a and 9 of the thermistor chip 8 on the back side of the heater substrate 2.
a is formed by applying a pattern of a conductive material paste such as Ag on the surface of the heater substrate 2 by screen printing or the like, followed by firing. The thermistor chip 8 connects the electrodes 8a on the thermistor chip 8 side to the wiring portions 9.9.
Are connected by a conductive adhesive 11.

The heater 10 has a heater base 2 on which a heat generating layer pattern 3 and a conductor pattern 4 are formed, and the side covered with the glass layer 7 as a heater surface protective layer is the heater front side, and the heater base 2 When the surface on which the thermistor chip 8 and the like are provided is the heater back surface, the heater 10 is exposed downward so that the heater 10 is fitted into a groove 20 a provided along the length on the lower surface of the heater holder 20. It is fixed and supported. The fixing film 21 slides in close contact with the heater surface, which is the downward surface of the heater 10, at the fixing nip N. The glass layer 7 as a heater surface protection layer prevents abrasion and damage due to the close contact sliding of the fixing film 21 of the heating layer pattern 3 and the conductor pattern 4.

The heater 10 has a heating layer pattern 3
To the power supply electrode patterns 5, 6,
When current is applied through the conductive pattern 4 and the conductive pattern 4a, the heat generating layer pattern 3 generates heat over its entire length, and the entire heater 10 rapidly rises in temperature. The temperature rise of the heater 10 is detected by the thermistor chip 8 disposed on the back side of the heater, and the detected temperature information is transmitted to the wiring section 9.
9. Feedback is sent to a temperature control circuit (not shown) via the electrode portions 9a. The temperature control circuit controls the power supply from the power supply unit to the heating layer pattern 3 so that the heater temperature detected by the thermistor chip 8 is maintained at a predetermined substantially constant temperature (fixing temperature). That is, heater 1
0 is heated and adjusted to a predetermined fixing temperature. The fixing nip N is heated by the heat of the heater 10 via the fixing film 21, and the recording material P introduced into the fixing nip N is heated by the heater 10 via the fixing film 21.

Such a film heating type heating apparatus can use a so-called ceramic heater 10 having a high heat-up and a low heat capacity as a heating element, and a thin film film also having a low heat capacity as a film material 21. A pressure roller 22 having an elastic layer for high rigidity of 10 is flattened at a pressure contact portion following a flat lower surface of the heater 10 pressed against the pressure roller 22 to form a fixing nip portion N having a predetermined width, By heating only the fixing nip portion N, quick start and power saving heating and fixing are realized as compared with other heating devices such as a heat roller system.

[0028]

In the case of the above-mentioned heating and fixing apparatus of the film heating type, for example, the heater 10 as a heating element and the elastic pressing roller 22 as a pressing member are pressed against each other with a fixing film 21 interposed therebetween. The pressure distribution along the longitudinal direction of the formed fixing film / recording material heating section, ie, the fixing nip portion N, may bend because the elastic pressure roller 22 is supported at both ends and pressure is applied. Thus, the pressure at the central portion in the longitudinal direction of the fixing nip portion N may be reduced (pressure drop at the central portion in the longitudinal direction of the fixing nip portion N). In the pressure drop portion of such a pressure distribution, the amount of heat supplied from the heater to the fixing film is smaller than in other portions, so that the image fixability of the recording material may become non-uniform.

The temperature distribution along the longitudinal direction of the fixing nip portion N may be such that heat is taken to the surroundings through the metal core of the elastic pressure roller 22 and the temperature at both ends decreases. Gain (heat dissipation loss at the end). In such a case, the image fixing property of the recording material portion corresponding to both ends of the fixing nip portion in the longitudinal direction where the temperature is lowered deteriorates,
The image fixability of the recording material may become non-uniform.

If the temperature of the fixing nip N at the recording material entrance is higher than a predetermined temperature, the recording material that has entered the fixing nip N is rapidly heated at the fixing nip entrance. This causes a so-called “tailing” phenomenon in which the unfixed toner image T on the recording material is blown off in the recording material conveyance direction due to the generated water vapor pressure, and the image quality is reduced.

Accordingly, the present invention is to make it possible to easily provide a desired distribution of heat supply in the longitudinal direction and the width direction of the material to be heated of the heating body, that is, the material to be heated of the heating body. It is possible to easily and arbitrarily adjust the heat supply amount distribution as desired over the entire heating surface. In the case of a heat fixing device, in the heat fixing device, the pressure nip portion of the fixing nip, which is the heating portion of the recording material, and the heat radiation. Uniform fixing performance by easily adjusting the distribution of heat supply in the heating surface of the material to be heated so as to correct (compensate) the loss portion or not to raise the temperature at the entrance of the fixing nip. And to prevent tailing phenomenon.

[0032]

According to the present invention, there is provided a heating element, a heating apparatus, and an image forming apparatus having the following constitutions.

(1) A heating element for heating a material to be heated,
A pattern is formed on the surface of the heating body on the side of heating the material to be heated with a material having a lower thermal conductivity than that of the substrate of the heating body, and an arbitrary heat supply amount distribution is provided within the surface of the heating body to be heated. A heating element characterized in that:

(2) A heating element for heating a material to be heated, which is basically composed of a heating element substrate and a resistance heating element provided on one side of the heating element substrate. The surface opposite to the side on which the body is provided is the surface on the side to be heated of the material to be heated, and a pattern is formed on the surface of the heated base material with a material having a lower thermal conductivity than the heated base material. A heating element characterized in that an arbitrary heat supply amount distribution is provided in a heated surface of a material to be heated of the heating element.

(3) The heating element according to (1) or (2), wherein the heating element substrate is ceramic.

(4) The heating element according to any one of (1) to (3), wherein the material having a lower thermal conductivity than the substrate of the heating element is glass.

(5) The heating element according to any one of (1) to (4), wherein the thickness of the pattern of the material whose thermal conductivity is inferior to that of the heating element substrate is not uniform.

(6) The heating element according to any one of (1) to (5), wherein the width of the pattern of the material whose thermal conductivity is inferior to that of the heating element substrate is not uniform.

(7) The pattern of a material whose thermal conductivity is inferior to that of the heating element substrate is composed of a composite of patterns of two or more materials having different thermal conductivity. (1)
To (6).

(8) A heating device comprising the heating element according to any one of claims 1 to 6 as a heating element for heating a material to be heated.

(9) The heating device according to (8), wherein the heating element is fixedly supported by the support member.

(10) A heating element fixedly supported by a supporting member and a film that slides in contact with the heating element, and heat energy is applied to the material to be heated by heat from the heating element via the film. A heating device, wherein the heating body is any one of (1) to (6).

(11) The heating device according to (10), further comprising a pressure member that presses against the heating body with the film interposed therebetween to form a nip portion as a heated material heating portion.

(12) The method according to (8), wherein the material to be heated is a recording material carrying an unfixed image, and the apparatus is a heat fixing device for thermally fixing the unfixed image to the recording material. 11) The heating device of any one of the above.

(13) An image forming means for forming an unfixed image on the recording material, and a heat fixing means for thermally fixing the unfixed image on the recording material, wherein the heat fixing means are defined by (8) to (8). 12) An image forming apparatus, which is any one of the heating apparatuses.

<Operation> A pattern is formed on the surface of the heating body on the side where the material to be heated is heated, using a material having a lower thermal conductivity than the base material of the heating body, and the thickness, width, material, etc. of the material pattern. By adjusting the amount of heat, the amount of heat supplied to the material pattern forming portion of the heating surface of the material to be heated can be more easily and arbitrarily controlled than the amount of heat supplied to the material pattern non-forming portion or another material pattern forming portion. As a result, it is possible to easily provide an arbitrary heat supply amount distribution in the longitudinal direction or the width direction of the material to be heated of the heating body. That is, it is possible to easily and arbitrarily adjust the heat supply amount distribution over the entire surface of the heated material to be heated.

Thus, in the heat fixing device, the pressure drop portion and the radiation loss portion of the fixing nip portion, which is the recording material heating portion, are corrected (compensated), that is, the heating member cover corresponding to the pressure drop portion. The amount of heat supplied to the heating material heating surface portion should be higher than the other heating surface portions so that the required heat supply amount distribution is greater than the other heating surface portions, or the heat supply amount to the heating object heated material heating surface portion corresponding to the heat dissipation loss portion is different. By forming a pattern with a material whose thermal conductivity is lower than that of the heater base material on the heated surface of the material to be heated, so that the distribution of heat supply becomes more necessary than that of Can be secured.

Further, the heating element is heated so that the amount of heat supplied to the heating surface of the material to be heated corresponding to the entrance of the fixing nip is suppressed and the distribution of heat supplied does not increase the temperature of the entrance of the fixing nip. By forming a pattern on the material heating surface with a material having a lower thermal conductivity than the heating element base material, the tailing phenomenon can be prevented.

[0049]

BEST MODE FOR CARRYING OUT THE INVENTION

<Embodiment 1> (FIGS. 1 to 5) (1) Example of Image Forming Apparatus FIG. 1 is a schematic configuration diagram of an example of an image forming apparatus. The image forming apparatus of this embodiment is a laser beam printer using a transfer type electrophotographic process.

Reference numeral 101 denotes a photosensitive drum as an image carrier, and a photosensitive material such as OPC (organic photoconductor), amorphous Se, and amorphous Si is formed on a cylindrical substrate such as aluminum or nickel.

The photosensitive drum 101 is driven to rotate at a predetermined peripheral speed (process speed) in a clockwise direction indicated by an arrow.
During the rotation process, the charging roller 102 as a charging unit is uniformly charged to a predetermined polarity and potential.

Next, the charge control surface of the rotating photosensitive drum 101 is subjected to modulation control (corresponding to a time-series electric digital pixel signal of target image information output from a laser scanning exposure apparatus (laser beam scanner) 103). ON / OF
The scanning exposure is performed by the laser beam L subjected to the F control, and an electrostatic latent image corresponding to target image information is formed on the rotating photosensitive drum surface.

The electrostatic latent image formed on the surface of the rotating photosensitive drum is developed (visualized) as a toner image by the developing device 104. As a development method, a jumping development method, a two-component development method, an FEED development method, or the like is used, and a combination of image exposure and reversal development is often used.

On the other hand, a nip portion (transfer nip portion) n between the rotating photosensitive drum 101 and a transfer roller 105 as a transfer means brought into contact with the photosensitive drum 101 from a paper feeding mechanism (not shown) is used as a recording material. The transfer material P is fed at a predetermined control timing, is nipped and conveyed at a constant pressing force between the transfer nip n, that is, between the photosensitive drum 101 and the transfer roller 105, and the toner image on the surface of the rotating photosensitive drum 101 is transferred to the transfer material P. Are sequentially transferred to the surface of

The transfer material P to which the toner image has been transferred at the transfer nip portion n is separated from the surface of the photosensitive drum 101, conveyed to a heat fixing device 100 as a heating device, heat-fixed the toner image, and discharged and conveyed. You.

After the transfer of the toner image to the transfer material P, the surface of the photosensitive drum 101 is cleaned by the cleaning device 106 to remove the residual toner remaining after transfer and other adhered contaminants, and is repeatedly used for image formation.

(2) Heat Fixing Apparatus 100 a) Overall Schematic Configuration of Apparatus 100 FIG. 2 is a schematic configuration diagram of the heating fixing apparatus 100 of this embodiment. The heat fixing device 100 of this embodiment is disclosed in Japanese Patent Application Laid-Open No. 4-44075.
No. 44083 to a pressure roller driving type / tensionless type film heating type heating device disclosed in Japanese Patent Application Laid-open No. Constituent members and portions common to those in the above-described devices of FIGS. 14 and 15 are denoted by the same reference numerals, and description thereof is omitted.

The heater holder (heater supporting member) 20 is a member having a substantially semicircular trough-shaped cross section formed of liquid crystal polymer, phenol resin, PPS, PEEK, or the like. The heater 1 is fitted and fixedly supported in the groove 20a provided. The structure of the heater 1 will be described in detail in the following section b).

The fixing film 21 is a cylindrical film material, and is loosely fitted to a heater holder 20 on which the heater 1 is fixedly supported.

Then, the heater 1 on the lower surface of the heater holder 20 and the elastic pressing roller 22 as a pressing member are pressed with a predetermined pressing force against the elasticity of the elastic pressing roller 22 with the fixing film 21 interposed therebetween. Thus, a fixing nip portion N having a predetermined width as a heating portion is formed.

The elastic pressure roller 22 is composed of a core metal and an elastic layer formed by foaming heat-resistant rubber such as silicone rubber or fluorine rubber or silicone rubber on the outside thereof. A release layer such as PFA / PTFE / FEP may be formed outside the elastic layer. In this embodiment, both ends of the elastic pressure roller 22 are sufficiently pressed and urged toward the heater holder 20 by a pressing means (not shown) to fix the fixing film 2.
The fixing nip portion N necessary for heat fixing is formed by pressing the heater 1 with the heater 1 therebetween.

The elastic pressure roller 22 is driven to rotate in a counterclockwise direction indicated by an arrow by a driving means M (pressure roller drive type). The cylindrical fixing film 2 is formed by the contact frictional force at the fixing nip portion N between the roller 22 and the outer surface of the fixing film 21 by the rotational driving of the elastic pressure roller 22.
1, the fixing film 21 rotates in the clockwise direction as indicated by the arrow while the inner surface of the film slides on the outer periphery of the heater holder 20 in the fixing nip portion N while closely contacting the downward surface of the heater 1.

When the fixing film 21 is rotated by the rotation of the elastic pressure roller 22, and the heater 1 is heated to a predetermined temperature by energizing the heater 1,
A transfer material P as a recording material carrying an unfixed toner image T is introduced between the fixing film 21 and the elastic pressure roller 22 in the fixing nip N, and the toner image carrying surface comes into close contact with the outer surface of the fixing film 21. The heat from the heater 1 is applied to the transfer material P via the fixing film 21 by passing through the fixing nip portion N together with the fixing film 21, and the unfixed toner image T is heat-fixed Ta on the surface of the transfer material P. . The transfer material P passing through the fixing nip N is separated from the surface of the fixing film 21 by a curvature and is discharged and conveyed.

The heater holder 20 functions as a support member for the heater 1 and pressurizes the fixing nip N.
It also serves to improve the rotational conveyance stability of the cylindrical fixing film 21.

The fixing film 21 has an inner surface on the lower surface of the heater 1 at the fixing nip portion N and a fixing nip portion N
Is rotated while sliding on the outer surface of the heater holder 20 in the vicinity of. In order to rotate the fixing film 21 smoothly with low torque, the frictional resistance between the heater 1 and the heater holder 20 and the fixing film 21 is reduced. Therefore, a small amount of lubricant such as heat-resistant grease is interposed between the fixing film 21 and the heater 1 and the heater holder 20. Thus, the fixing film 21 can rotate smoothly.

The fixing film 21 is a member having a small heat capacity.
Polyimide, polyamide imide, PEEK, PES, PPS, PFA, with heat resistance and thermoplasticity with the following thickness
Films such as PTFE and FEP. Further, a film having sufficient strength and excellent durability for constituting a heat fixing device having a long service life is required to have a thickness of 20 μm or more. Therefore, the thickness of the fixing film 21 is 20 μm.
It is optimal that the thickness is at least m and at most 100 μm. Further, in order to prevent offset and to ensure the separation of the recording material, the surface layer of the fixing film is a mixture of a heat-resistant resin having good releasability such as PFA, PTFE, FEP, and silicone resin, or coated alone. .

B) Heater 1 FIG. 3 is an enlarged cross-sectional model view of a main part of the heating and fixing apparatus 100, and FIG.
(B) is a model drawing of the back side similarly. FIG. 14 and FIG.
The same reference numerals are given to the constituent members and portions common to the heater 10 of No. 5, and the description will not be repeated.

The heater 1 in the present example has a basic structure including a ceramic base (heater base) 2 and a heating layer 3 provided on one surface (back side) of the ceramic base 2.
The substrate surface (surface side) of the ceramic substrate 2 opposite to the substrate surface on which the heat generating layer 3 is provided is a surface for applying thermal energy to the material to be heated. As shown in FIG. 4A, a pattern layer 13 (hereinafter, referred to as a low thermal conductivity pattern layer) is formed of a material that is inferior to the ceramic base material 2 so that a desired amount of heat can be supplied to the heating surface of the heater 1. This is a backside heating type ceramic heater with a distribution.

The ceramic substrate 2 as a heater substrate is made of, for example, alumina (Al ₂ O ₃ ) / aluminum nitride (A
1N), for example, a length of 240 mm and a width of 10 mm
And a horizontally long plate material having a thickness of 1 mm.

In this embodiment, the low thermal conductivity pattern layer 13 is, for example, a glass coat having a thickness of about 50 μm. Usually, the thermal conductivity of glass is about 2 to 3 × 10 ⁻³ (cal / cm sec K), which is 10 to 100 times lower than that of the ceramic substrate. By the way, the thermal conductivity of alumina is 5 × 10 ^-2 (ca
l / cm sec K), 5 × 10 for aluminum nitride
^-1 (cal / cm sec K).

On the back side of the heater, as shown in FIG. 4B, the heating layer pattern 3, the conductive pattern 4, the conductive pattern 4a, the electrode patterns 5.6, the thermistor 12, and the wiring sections 9.9 for the thermistor 12 , Electrode portions 9a, 9a and the like.

In the present embodiment, the heat generating layer pattern 3 is formed by applying a silver palladium paste by screen printing along a longitudinal length of the back surface of the ceramic base material into a narrow strip having a thickness of 10 μm and a width of 1 to 3 mm, followed by firing. 4 is Ag
The paste is formed by applying a pattern on the back surface of the ceramic substrate 2 by screen printing and firing the paste.

The thermistor 12 forms particles of an alloy such as cobalt, manganese, nickel, ruthenium, oxides, ceramics such as platinum or barium titanate on the back surface of the ceramic substrate between the heating layer pattern 3 and the conductor pattern 4. It was mixed with a glass paste material and screen-printed on the back surface of the ceramic substrate to form a thin layer type. The wiring portions 9.9 of the thermistor 12 are arranged at the surface of the ceramic base material between the heat generating layer pattern 3 and the conductor pattern 4.
The heating layer pattern 3 is separated from the conductor pattern 4 by an insulation distance.
It is arranged in parallel with the conductor pattern 4.

The heater 1 has a groove 2 formed on the lower surface of the heater holder 20 along the length of the heater holder 20 by exposing the surface side on which the low thermal conductivity pattern layer 13 is formed to be exposed downward.
0a and fixedly supported. In this example, the seat 14 corresponding to the rear surface of the heater of the heater holder 20 is lowered, and a gap 14 as a non-contact portion between the heater 1 and the heater holder 20 (FIG. ) Is made to exist.

The heater 1 in this example has a heating layer 3 on the back side of the ceramic base 2, and a base surface opposite to the base surface provided with the heating layer 3 of the ceramic base 2, that is, the base surface. A backside heating type ceramic heater in which the surface side of the material is a surface for applying thermal energy to the material to be heated, and a low thermal conductivity pattern layer 13 is formed on the surface of the substrate,
The fixing film 21 slides in contact with the heater surface, that is, the surface of the ceramic substrate 2 on which the low thermal conductivity pattern layer 13 is formed, in the fixing nip portion N, and
Heat generated by the heat generating layer pattern 3 is transmitted to the fixing film 21 and the recording material P through the ceramic base 2.

. In the case of FIG. 4A, the glass coat 13 formed as a low thermal conductivity pattern layer formed on the heater surface side corrects the pressure distribution in the longitudinal direction of the fixing nip N to form the fixing nip N. The pattern is such that the heat supply amount distribution in the longitudinal direction is substantially uniform.

That is, the fixing nip N which is a fixing film / recording material heating section formed by pressing the heater 1 as a heating body and the elastic pressing roller 22 as a pressing member with the fixing film 21 interposed therebetween. The pressure distribution along the longitudinal direction is
Since the elastic pressure roller 22 is supported at both ends and is applied with pressure to cause deflection, the pressure at the center in the longitudinal direction of the fixing nip N may be reduced (fixing nip). Pressure drop at the center in the longitudinal direction of the portion N). In the pressure drop portion of such a pressure distribution, the amount of heat supplied from the heater 1 to the fixing film 21 side is smaller than in other portions, so that the image fixing property of the recording material may become non-uniform.

Therefore, in the case of the present embodiment, the pattern of the glass coat 13 as the low thermal conductivity pattern layer formed and provided on the surface side of the heater is applied with pressure in the longitudinal direction of the fixing nip N as shown in FIG. When the width at the central portion corresponding to the pressure drop portion of the distribution is Wa and the width at both ends is Wb, the pattern is such that Wa <Wb. This allows
The amount of heat supplied from the heater 1 to the fixing film 21 at the central portion corresponding to the pressure drop portion of the pressure distribution in the longitudinal direction of the fixing nip portion N can be increased as compared with the both end portions. The shortage of pressure in the central portion in the longitudinal direction of N can be compensated for by heat, and uniform fixability can be ensured.

[0079] Further, the temperature distribution along the longitudinal direction of the fixing nip portion N may be such that heat is deprived to the surroundings through the core metal of the elastic pressure roller 22 and the temperature at both ends decreases (end). Heat loss in the part). Then, the image fixing property of the recording material portion corresponding to both ends in the longitudinal direction of the fixing nip portion where the temperature is lowered is deteriorated, and the image fixing property of the recording material may become non-uniform.

In such a case, as shown in FIG. 5A, a glass coat is formed on the center of the heater nip portion N in the longitudinal direction of the fixing nip portion N, and a glass coat is formed on both ends. By forming and providing the low thermal conductivity pattern layer 13 in an uncoated form, the fixing nip N
In the longitudinal direction, the amount of heat supplied to both end portions can be relatively increased as compared with the central portion, so that the fixability at the end portions can also be improved.

[0081] If the temperature of the fixing nip N at the recording material entrance is higher than a predetermined temperature, the recording material entering the fixing nip N is rapidly heated at the fixing nip entrance. The generated water vapor pressure causes a so-called “tailing” phenomenon in which the unfixed toner image T on the recording material is blown backward in the recording material conveyance direction, and the image is deteriorated.

In such a case, as shown in FIG. 5B, a portion corresponding to the entrance of the fixing nip portion of the fixing nip portion N (the fixing film / recording material on the heater surface side) is provided on the heater surface side. By forming and providing a narrow band-shaped low thermal conductivity pattern layer 13 along the length of the fixing nip portion (on the upstream side in the transport direction), the amount of heat supply at the recording material inlet portion of the fixing nip portion N is reduced to reduce the heat supply amount. Can be prevented from reaching a predetermined high temperature or more, and the tailing phenomenon can be prevented.

As described above, the pattern of the glass coat 13 as the low thermal conductivity pattern layer makes it possible to easily have a desired distribution of heat supply in the heated surface of the material to be heated of the heater 1 as the heating element. In the heat fixing device, problems such as defective fixing and tailing can be solved.

<Embodiment 2> (FIGS. 6 to 8). FIGS. 6A and 6B respectively show a glass coat 13 as a low thermal conductivity pattern layer formed and provided on the surface side of the heater, the thickness of which is changed in the longitudinal direction of the fixing nip portion N.

That is, in (a), the thickness of the glass coat 13 is made gradually smaller as the thickness tb at both ends of the fixing nip N becomes smaller toward the end than the thickness ta at the center in the longitudinal direction. As described above, the glass coat 13 in the form in which the thickness is changed in the longitudinal direction of the fixing nip portion N is adjusted by changing the moving speed of the glass coat paste squeezing device when the glass coat is formed by screen printing. Can be formed.

(B) is a configuration in which the thickness of the glass coat 13 is set such that the thickness tb at both ends is ta> tb with respect to the thickness ta at the central portion in the longitudinal direction of the fixing nip N by repeating the printing process of the glass coat a plurality of times. It is what was made.

In the glass-coated heaters shown in FIGS. 6A and 6B, heat is taken to the surroundings through the core of the elastic pressure roller 22 and the temperature distribution along the longitudinal direction of the fixing nip portion N is reduced. Heat supply (heat conduction) at the end of the heater against the case where the temperature drops at both ends (heat loss at the end)
Is relatively higher than that at the center, so that the fixing property at the end can be improved, which is effective.

[0088] 7A and 7B are opposite to the thicknesses ta at the both ends of the fixing nip N with respect to the thickness ta at the central portion in the longitudinal direction, contrary to FIGS. 6A and 6B.
b is thickened.

The glass coat 13 shown in FIG. 7A can be formed by adjusting the thickness by changing the moving speed of the glass coat paste squeezer when the coat is formed by screen printing.

(B) shows a configuration in which the thickness of the glass coat 13 is set such that the thickness tb of both ends is ta <tb with respect to the thickness ta of the central portion in the longitudinal direction of the fixing nip N by repeating the glass coating printing process a plurality of times. It is what was made.

7A and 7B, the amount of heat supplied at the central portion in the longitudinal direction of the fixing nip portion N can be made larger than that at both end portions. This is effective when the pressure is insufficient at the central portion in the longitudinal direction (pressure drop at the central portion in the longitudinal direction of the fixing nip N).

[0092] FIGS. 8A and 8B show low thermal conductivity patterns each composed of a composite of patterns 13a and 13b of two materials having different thermal conductivity.

FIG. 8A shows a state in which a first glass coat 13a is formed on the heater surface side in the center of the fixing nip portion N in the longitudinal direction, and the first glass coat 13a is covered. Further, a second glass coat 13b is formed and provided on both ends in the longitudinal direction of the fixing nip portion N.

The second glass coat 13b is made of a material having better heat conductivity than the first glass coat 13a, and corresponds to the second glass coat 13b corresponding to both longitudinal ends of the fixing nip N. Is gradually thinned toward the end.

In the case of the glass-coated heater of this example, the heat supply amount at both ends in the longitudinal direction of the fixing nip portion N is better than that at the center portion, and heat is taken to the surroundings through the core metal of the elastic pressure roller 22. When the temperature distribution along the longitudinal direction of the fixing nip portion N decreases at both ends (radiation loss at the ends), the amount of heat supplied (heat conduction) at the ends of the heater
Is relatively higher than that at the center, so that the fixing property at the end can be improved, which is effective.

Further, since the second glass coat 13b is applied to the entire area inside the fixing nip portion of the heater 1, the slidability of the fixing film 21 with respect to the heater surface is improved, and the wear of the fixing film can be prevented.

(B) A first glass coat 13a is formed at the center of the heater nip portion N in the longitudinal direction on the front surface side of the heater.
a, a second glass coat 13b is formed at both ends in the longitudinal direction of the fixing nip portion N so that the second glass coat 13b is more thermally conductive than the first glass coat 13a. Good material.

Also in this case, the heat supply amount at both ends in the longitudinal direction of the fixing nip portion N is better than that at the center portion, and heat is taken to the surroundings through the core metal of the elastic pressure roller 22, so that the heat is supplied in the longitudinal direction of the fixing nip portion N. In the case where the temperature distribution along the temperature decreases at both ends, the heat supply amount at the end of the heater can be relatively increased from that at the center, so that the fixing property at the end can be improved, which is effective. .

Although not shown, the material of the glass coat layer may be changed between the upstream side and the downstream side in the fixing film / recording material transport direction A on the heater surface. by this,
The tailing can be improved.

<Embodiment 3> (FIGS. 9 and 10) Heating layer pattern 3 and conductor pattern 4 of ceramic heater 1
a, the electrode patterns 5 and 6, the thermistor 12, the wiring portions 9 and 9 for the thermistor 12, the electrode portions 9 a and 9 a, the low thermal conductivity patterns 13, 13 a, and 13 b can be formed and provided by a method such as screen printing. it can.

FIGS. 9 and 10 show how the heat generating layer pattern 3 is formed by screen printing, for example.

In FIG. 9, 2A is a heating element (heater).
One large-sized ceramic substrate (hereinafter, referred to as an original plate) that can take a plurality of pieces. The original plate 2A of this example is, for example, an alumina plate having a thickness of 1 mm, a width of 70 mm, and a length of 240 mm, and takes 11 heating elements 1. The original plate 2A is preliminarily provided with grooves or perforation lines a at equal intervals (about 6.36 mm) by a laser scribe or a mold so as to be easily divided and separated into individual heating elements 1 thereafter.

Reference numeral 200 denotes a support for holding the original plate 2A. The original plate 2A is positioned and set on the support base 200 at a predetermined position, and the state is attracted by a vacuum from the back surface to stably hold the original plate 2A so that no positional deviation occurs.

Reference numeral 201 denotes a screen for printing a heating layer pattern, and reference numeral 202 denotes a screen frame in which the screen 201 is stretched and held under tension. Reference numeral 201a denotes a print pattern portion of the screen 201, and a total of 11 parallel stripe patterns for printing the heating layer pattern 3 on predetermined surface positions corresponding to the individual heating portions of the original plate 2A having 11 heating members, respectively. It is. The screen 201 is coarse only in the printing pattern portion 201a,
Only in this portion 201a, the resistor paste for forming the heating layer pattern can pass.

Numeral 203 denotes a printed pattern portion 2 of the screen 201 by spreading the resistor paste on the screen 201.
This is a squeezing device for adhering the resistor paste to the surface of the ceramic base material at a constant thickness from the eye of 01a.

Reference numeral 204 denotes a dispenser.
This is for supplying a fixed amount of the resistor paste before the moving direction of 03. The resistor paste is supplied to the dispenser 204 from a tank (not shown).

Then, the screen 201 is positioned and superimposed on the support table 200 on which the original plate 2A is positioned as shown in FIG. 10, and after the resistor paste is supplied by the dispenser 204 before the drawer 203, the drawer 203 is removed.
Is moved in the direction of the arrow S, the heating layer pattern 3 is printed at a predetermined surface position corresponding to each heating element portion of the original plate 2A having 11 heating elements, and dried.

<Embodiment 4> (FIG. 11) As shown in FIG. 3 described above, the heater 1 is fixedly supported on the heater holder 20 by lowering the seat surface of the heater holder 20 at the portion corresponding to the heater back surface. By providing the air gap 14 as a non-contact portion between the heater holder 1 and the heater holder 20, a decrease in thermal efficiency due to heat leak to the heater rear side due to the heat insulating effect of the air in the air gap 14 can be improved. .

As shown in FIG. 11, by providing a heat insulating layer 15 such as a glass layer on the back surface of the heater 1, it is possible to improve the reduction in thermal efficiency due to heat leak to the back surface of the heater.

In the case of FIG. 11, a safety element 16 is further provided in contact with the glass layer 15 as a heat insulating layer on the back surface of the heater 1. The safety element 16 is, for example, a thermal fuse or a thermoswitch, and operates when the heater 1 runs out of control and overheats, and has a role of urgently shutting off the power supply to the heating layer 3.

Even if the heater 1 is of a backside heating type, a glass layer 1 serving as a heat insulating layer is provided on the backside of the heater 1.
By providing 5, it is possible to further reduce the decrease in thermal efficiency due to heat leak to the back side of the heater,
Due to the insulating property of the glass layer 15, the safety element 16 is connected to the AC line of the heater 1 (heating layer pattern 3 / conductor pattern 4).
As a result, the response of the safety element 16 can be accelerated, and the safety of the device can be increased.

In the case of FIG. 11, a glass layer 15 is provided on the back side of the heater 1 as a heat insulating layer, and a gap 14 is provided between the heater 1 and the heater holder 20. In this case, The glass layer 15 as the heat insulating layer and the gap 14 can further reduce the decrease in thermal efficiency due to heat leak to the back side of the heater.

<Embodiment 5> (FIG. 12) FIGS. 12A, 12B, and 12C are schematic diagrams of another configuration example of a film heating type heating device (heating fixing device).

FIG. 13A shows three parallel members 31 and 32 of a first film suspension roller 31, a second film suspension roller 32, and a heater 1 fixedly supported by a heater holder 20. An endless belt-shaped fixing film (heat-resistant film material) 21 is suspended and stretched between the fixing films 21, and the fixing film 21 is pressed into contact with the heater 1 with the pressing roller 22 disposed therebetween. The first
Of the film suspension roller 31 or the pressure roller 22 as a film drive roller. When the first film suspension roller 31 is used as a driving roller, the pressure roller 22 is driven to rotate.

In the case (b), an endless belt-shaped fixing film 21 is suspended and stretched between two members 1 and 33 of a heater 1 fixedly supported by a heater holder 20 and one film suspension roller 33. Then, the pressure roller 22 is disposed in pressure contact with the heater 1 with the fixing film 21 interposed therebetween,
In this configuration, the fixing film 21 is rotated and conveyed as a film suspension roller 33 or the pressure roller 22 as a film driving roller. First film hanging roller 3
When the driving roller 3 is used, the pressure roller 22 is driven to rotate.

In the case of (c), the fixing film 21 is not an endless belt-like film but a long end film wound in a roll.
Heater 1 fixedly supported by heater holder 20 from the side
, The pressure film 22 is pressed against the heater 1 with the fixing film 21 interposed therebetween, and the fixing film 21 travels and conveys to the winding shaft 35 side. The pressure roller 22 can be a film drive roller.

<Others> 1) In the present invention, the configuration of the heating element (heater) 1 is arbitrary, and is not limited to the backside heating type ceramic heater of the embodiment. Also, a ceramic heater that is not a backside heat generation type may be used.

As in the example of the apparatus shown in FIG. 13, the heating element is an iron plate that generates an eddy current by an electromagnetic (magnetic) induction heating member 1A, that is, an eddy current due to a high frequency magnetic field generated from a magnetic field generating means 24 such as an excitation coil. And the like.

In short, the present invention provides a pattern (low thermal conductivity pattern) 13 (13a) made of a material having a lower thermal conductivity than the base material of the heating body on the surface of the heating body 1.1A on the side to be heated of the material to be heated.
13b) is formed to provide a desired distribution of heat supply in the surface of the material to be heated of the heating element 1.1A.

The low thermal conductivity pattern 13 (13a
b) and the heat insulating layer 15 are not limited to glass;
A heat-resistant resin such as TFE can also be used.

2) In the case where the heating element 1 basically has the heating element base 2 and the heat generating layer 3 formed thereon, the number and pattern of the heat generating layers 3 are limited to those of the embodiment. It is not a thing to be done and is arbitrary. When a plurality of heat generating layers 3 are used, the individual heat generating layers may have different resistance values per unit length, materials, widths, thicknesses, and the like.

3) When the heating element has a heating element base 2 and a heating layer 3 formed on the heating element as a basic structure, and is of a backside heating type, the heating element base is a surface for applying heat energy to a material to be heated. On the surface side, an arbitrary functional layer, for example, a diamond-like thin layer as a high heat conductive lubricating layer (high heat conductive hard layer) for reducing contact friction resistance with a fixing film or a material to be heated, and preventing frictional electrification, etc .; A hard chromium layer or the like as a lubricating layer having high thermal conductivity can be formed.

4) The heating element according to the present invention is not limited to the film heating type heating apparatus (fixing apparatus) of the embodiment, but can be used as a heating element of a heating apparatus of another configuration.

5) The heating device of the present invention is not only a heating and fixing device of the embodiment, but also a device for heating a recording material carrying an image to improve its surface properties (such as gloss), and a device for supposedly attaching. It can be widely used as a heating device such as a device for performing a drying process or a heat lamination process.

[0125]

As described above, according to the present invention, a pattern is formed on a surface of a heating body on a side on which a material to be heated is heated, using a material having a lower thermal conductivity than a heating body base material. By adjusting the thickness and width of the material pattern, the material of the material, and the like, the heat supply amount of the material pattern forming portion of the heating surface of the heating target material to be heated is supplied to the material pattern non-forming portion or another material pattern forming portion. The desired amount can be suppressed more easily than the amount, and a desired and desired heat supply amount distribution can be easily provided in the longitudinal direction or the width direction in the heated material heating surface of the heating body. That is, it is possible to easily and arbitrarily adjust the heat supply amount distribution over the entire surface of the heated material to be heated.

Thus, in the heat fixing device, the pressure drop portion and the heat radiation loss portion of the fixing nip portion, which is the recording material heating portion, are corrected (compensated), that is, the heating member cover corresponding to the pressure drop portion. The amount of heat supplied to the heating material heating surface portion should be higher than the other heating surface portions so that the required heat supply amount distribution is greater than the other heating surface portions, or the heat supply amount to the heating object heated material heating surface portion corresponding to the heat dissipation loss portion is different. By forming a pattern with a material whose thermal conductivity is lower than that of the heater base material on the heated surface of the material to be heated, so that the distribution of heat supply becomes more necessary than that of Can be secured.

Further, the heating element is heated so that the heat supply amount at the heating surface of the heating member to be heated corresponding to the entrance portion of the fixing nip portion is suppressed and the heat supply amount distribution does not increase the temperature at the entrance portion of the fixing nip portion. By forming a pattern on the material heating surface with a material having a lower thermal conductivity than the heating element base material, the tailing phenomenon can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an example of an image forming apparatus.

FIG. 2 is a schematic diagram illustrating a configuration of a heat fixing device according to a first embodiment.

FIG. 3 is an enlarged cross-sectional model view of a main part of the heat fixing device.

FIG. 4A is a front-side model of a heater (heating body).
(B) Back side model drawing

FIGS. 5 (a) and (b) are heater surface side model views showing other examples of low thermal conductivity patterns.

FIGS. 6 (a) and (b) are side model views of a heater showing an example in which the thickness of the low thermal conductivity pattern is changed (part 1).

FIGS. 7A and 7B are side model views of a heater showing an embodiment in which the thickness of the low thermal conductivity pattern is changed (part 2).

FIGS. 8 (a) and (b) are side model views of a heater showing an embodiment in which a low thermal conductivity pattern is formed by a composite of two materials having different thermal conductivity.

FIG. 9 is an explanatory view of a screen printing method (part 1).

FIG. 10 is an explanatory view of a screen printing method (part 2).

FIG. 11 is an enlarged cross-sectional schematic view of a main part of a heater or a heating and fixing device including the heater according to the fourth embodiment.

FIGS. 12A, 12B, and 12C are schematic diagrams of another configuration example of a film heating type heating device (heating fixing device).

FIG. 13 is an enlarged schematic cross-sectional view of a main part of an example of a heating apparatus using an electromagnetic induction heating method

FIG. 14 is a schematic cross-sectional view of a main part of an example of a film heating type heating device (heating fixing device).

15 (a) is a partially cutaway front-side model diagram of a heater, (b) is a back-side model diagram, and (c) is an enlarged cross-sectional model diagram ((b) diagram of a heater element portion of the heater). c)-(c)
Enlarged cross-sectional view along the line)

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 101 Photosensitive drum (image carrier) 102 Charging roller 103 Laser beam scanner 104 Developing device 105 Transfer roller 106 Cleaning device 100 Heat fixing device 1.1A.10 Heating body 20 Heating member support member (heater holder) 21 Fixing film (heat resistance)・ Thin film material 22 Pressure member (pressure roller) 2 Heating substrate (heater substrate) 3 Heat generation layer 12 Temperature sensing element (thermistor) 13 ・ 13a ・ 13b Low thermal conductivity pattern layer (glass layer) 14 void 15 Heat insulation layer 16 Safety element (temperature fuse, etc.) N Fixing nip P Heated material (recorded material, transfer material)

Claims (13)

[Claims] 1. A heating element for heating a material to be heated, wherein a pattern is formed on a surface of the heating element on a side on which the material to be heated is heated by using a material having a lower thermal conductivity than a substrate of the heating element. A heating element characterized in that an arbitrary heat supply amount distribution is provided in the heated surface of the material to be heated. 2. A heating element for heating a material to be heated, comprising a heating element substrate and a resistance heating element provided on one side of the heating element substrate. The surface on the side opposite to the side provided with is a surface on the side to heat the material to be heated,
On the heating body substrate surface on this side, a pattern is formed with a material having a lower thermal conductivity than the heating body base material, and an arbitrary heat supply amount distribution is provided within the heated material heating surface of the heating body. Heating body. 3. The heating element according to claim 1, wherein the heating element substrate is ceramic. 4. The heating element according to claim 1, wherein the material having a lower thermal conductivity than the heating element substrate is glass. 5. The heating element according to claim 1, wherein the thickness of the pattern of the material whose thermal conductivity is inferior to that of the heating element substrate is non-uniform. 6. The method according to claim 1, wherein the width of the pattern of the material having a thermal conductivity lower than that of the heater base material is non-uniform.
Heating body of any one of to 5; 7. The pattern of a material having a thermal conductivity lower than that of the heating element base material is composed of a composite of patterns of two or more materials having different thermal conductivity. One of the heating body. 8. A heating device comprising the heating element according to claim 1 as a heating element for heating a material to be heated. 9. The heating device according to claim 8, wherein the heating element is fixedly supported by the support member. 10. A heating body fixedly supported by a support member,
A heating device having a film that slides in contact with the heating element, and applying heat energy to the material to be heated by heat from the heating element through the film, wherein the heating element is any one of claims 1 to 6. A heating device, which is a heating element. 11. The heating apparatus according to claim 10, further comprising a pressure member that presses against the heating body with the film interposed therebetween to form a nip portion as a heated material heating section. 12. The recording medium according to claim 8, wherein the material to be heated is a recording material carrying an unfixed image, and the apparatus is a heat fixing device for thermally fixing the unfixed image to the recording material.
Any one of the heating devices of 1. 13. An image forming means for forming an unfixed image on a recording material, and a heat fixing means for thermally fixing the unfixed image to the recording material, wherein the heat fixing means is provided.
2. An image forming apparatus, which is the heating device according to any one of 2.